.container {
    position: relative;
    text-align: center;
    width: 100px;
  }
  
  .item {
    display: inline-block;
    height: 15px;
    width: 15px;
    border-radius: 50%;
    background: #969aec;;
    animation: item 10 ease-in-out infinite;
  }
  .b {
    animation-delay: .2s;
  }
  .c {
    animation-delay: .4s;
  }
  @keyframes item {
    0% {
      transform: translateY(0);
      opacity: 1;
    }
    50% {
      transform: translateY(20px);
      opacity: 0;
    }
    100% {
      transform: translateY(0);
      opacity: 1;
    }
  }
  